Parking assist system

ABSTRACT

In one aspect, the invention is directed to a parking assist system for a vehicle, wherein the parking assist system has two modes of operation. In a first mode a first overlay is added to an image of a rearward field of view displayed to the vehicle driver. The first overlay includes a representation of a target parking position. In a second mode a second overlay is added to the field of view displayed to the vehicle driver. The second overlay includes a representation of a projected path for the vehicle based on a current vehicle steering angle, and a representation of a target path segment for the vehicle.

CROSS REFERENCE TO RELATED APPLICATIONS

The present application is a 371 national phase filing of PCT Application No. PCT/US2010/043330, filed Jul. 27, 2010, which claims the filing benefit of U.S. provisional application Ser. No. 61/228,655, filed Jul. 27, 2009, which are hereby incorporated herein by reference in their entireties.

FIELD OF THE INVENTION

The present invention relates to a parking assist system for use in vehicles.

BACKGROUND OF THE INVENTION

Parking assist systems are currently available only on certain luxury vehicles, and are typically relatively complex systems that are either entirely or semi-autonomous, capable of steering and/or driving the vehicle into a parking spot. Such systems typically require significant processing power in order to determine a suitable path to follow during the parking maneuver. Such systems can be relatively expensive.

It would be advantageous if a parking assist system were available that required relatively less processing power, that was relatively simpler, and was relatively less expensive than some systems of the prior art.

SUMMARY OF THE INVENTION

In a first aspect, the invention is directed to a parking assist system for a vehicle, wherein a target parking position overlay is added to an image of a field of view of the camera displayed to the vehicle driver.

In a particular embodiment of the first aspect, the parking assist system includes a camera mounted to the vehicle and having a rearward field of view, a display in the vehicle connected to the camera and configured to display an image of the field of view, and a controller configured to add an overlay to the image of the field of view. The overlay includes a representation of a target parking position.

In a second aspect, the invention is directed to a parking assist system for a vehicle, that is configured to:

select a target path for the vehicle driver to follow while parking the vehicle,

to inform the driver of the vehicle's projected path based on the vehicle's steering angle,

and to inform the driver of whether the projected path matches the target path.

In a particular embodiment of the second aspect, the parking assist system includes a camera mounted to the vehicle and having a rearward field of view, a display in the vehicle connected to the camera and configured to display an image of the field of view, and a controller configured to add an overlay to the image of the field of view. The overlay includes a representation of a projected path for the vehicle based on a current vehicle steering angle, and a representation of a target path for the vehicle.

In a third aspect, the invention is directed to a parking assist system for a vehicle, wherein the parking assist system has two modes of operation. In a first mode a first overlay is added to an image of a rearward field of view of the camera displayed to the vehicle driver. The first overlay includes a representation of a target parking position. In a second mode a second overlay is added to the field of view displayed to the vehicle driver. The second overlay includes a representation of a projected path for the vehicle based on a current vehicle steering angle, and a representation of a target path segment for the vehicle.

In a particular embodiment of the third aspect, the parking assist system includes a camera mounted to the vehicle and having a rearward field of view, a display in the vehicle connected to the camera and configured to display an image of the field of view, and a controller configured to operate the parking assist system in two operating modes. In a first operating mode the controller is configured to add a first overlay to the image of the field of view, wherein the first overlay includes a representation of a target parking position. In a second operating mode the controller is configured to add a second overlay to the image of the field of view, wherein the second overlay includes a representation of a projected path for the vehicle based on a current vehicle steering angle, and a representation of a target path segment for the vehicle.

In a fourth aspect, the invention is directed to a parking assist system for a vehicle, wherein the parking assist system selects a plurality of target path segments for the vehicle to follow to park in a target parking spot, wherein each target path segment involves the vehicle having steering wheels pointed straight or at full lock.

In a particular embodiment of the fourth aspect, the parking assist system includes a camera mounted to the vehicle and having a rearward field of view, a display in the vehicle connected to the camera and configured to display an image of the field of view, and a controller configured to select a plurality of target path segments for the vehicle to follow to park in a target parking spot. Each target path segment involves the vehicle having the steering wheels pointed straight or at full lock.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention will now be described by way of example only with reference to the attached drawings, in which:

FIG. 1 is a schematic illustration of a parking assist system in accordance with an embodiment of the present invention;

FIG. 2 is a view of an image of a field of view of the camera on a display that is part of the parking assist system shown in FIG. 1;

FIG. 3 is a view of an image of a field of view of the camera on the display shown in FIG. 3, with the parking assist system in a parking spot locator mode;

FIG. 4 is a view of an image of a field of view of the camera on the display shown in FIG. 3, with the parking assist system in the parking spot locator mode, after the vehicle has traveled past a target parking spot;

FIG. 5 is a view of an image of a field of view on the display shown in FIG. 3, with the parking assist system in the parking spot locator mode, after the vehicle has backed up to a suitable position to park in the target parking spot;

FIG. 6 is a view of an image of a field of view on the display shown in FIG. 3, with the parking assist system in a parking guidance mode, showing the alignment between the projected path of the vehicle with a first target path segment for the vehicle;

FIGS. 7 a-7 d are views of an image of a field of view on the display shown in FIG. 3, with the parking assist system in the parking guidance mode, illustrating the progression of the vehicle along the first target path segment;

FIGS. 8 a-8 c are views of an image of a field of view on the display shown in FIG. 3, with the parking assist system in the parking guidance mode, showing the progression towards alignment between the projected path of the vehicle with a second target path segment for the vehicle;

FIGS. 9 a and 9 b are views of an image of a field of view on the display shown in FIG. 3, with the parking assist system in the parking guidance mode, illustrating the progression of the vehicle along the second target path segment;

FIGS. 10 a-10 d are views of an image of a field of view on the display shown in FIG. 3, with the parking assist system in the parking guidance mode, showing the progression towards alignment between the projected path of the vehicle with a third target path segment for the vehicle;

FIG. 11 is a view of an image of a field of view on the display shown in FIG. 3, with the parking assist system in the parking guidance mode, showing the vehicle having nearly completed the third target path segment for the vehicle; and

FIG. 12 is a view of an image of a field of view on the display shown in FIG. 3, with the parking system in the parking guidance mode, wherein the vehicle is parking in a perpendicular parking spot.

DETAILED DESCRIPTION OF THE INVENTION

Reference is made to FIG. 1, which shows a parking assist system 10 for use in a vehicle 11, in accordance with an embodiment of the present invention. The parking assist system includes a camera 12, a controller 14 and a display 16. The camera 12 is positioned on the vehicle 11 for rearward viewing and has a field of view generally shown at 18. The controller 14 communicates with the camera 12 and sends an image 20 of the field of view 18 (FIG. 2) to the display 16, which is positioned in the vehicle cabin. The display 16 is positioned to display the image 20 of the field of view 18 to the vehicle driver.

When the vehicle driver wants to use the parking assist system 10 (FIG. 1), he or she presses a button in the interior of the vehicle 11, which activates the parking assist system 10 in a first mode, which is a parking spot locator mode. When in the parking spot locator mode, the controller 14 adds an overlay 22 (FIG. 3) to the image 20, which assists the driver in finding a suitable parking spot for the vehicle 11 (FIG. 1). The overlay 22 (FIG. 3) includes a rectangle 24 which is a representation of a target parked position which is offset a selected distance behind and a selected distance laterally from the vehicle 11 (FIG. 1). The size of the rectangle 24 (FIG. 3) preferably represents substantially the length and further preferably represents substantially the width of the vehicle 11 (FIG. 1).

The overlay 22 (FIG. 3) also includes a line 26 extending along the outside edge (shown at 28) of the rectangle 24 (ie. the side edge of the rectangle 24 that faces outwardly from the parking spot).

The line 26 extends a selected distance forward of the rectangle 24 and a selected distance rearward of the rectangle 24 and assists the driver of the vehicle 11 in lining up the vehicle 11 to be parallel to the parking lane.

With the overlay 22 shown on the image 20, the driver drives along the road until he or she finds a potential parking spot, shown at 30 in FIG. 4. In the exemplary embodiment shown in the figures, the driver drove forward to find the potential parking spot 30. As shown in FIG. 4, the vehicle 11 has overshot the potential parking spot 30 and so the forward edge of the rectangle 24 is too far forward, overlapping with the vehicle (shown at 32) that is forward of the potential parking spot 30. Having driven too far forward, the driver may put vehicle 11 (FIG. 1) into reverse gear in order to back up to superimpose the rectangle 24 on the potential parking spot 30.

When the vehicle is in reverse, a representation 34 of the projected path of the vehicle is added to the included in the overlay 22 that is provided with the image 20 shown on the display 16. The representation 34 is based on the steering angle of the vehicle and is updated as the steering angle changes.

The representation 34 includes several features such as lateral edge lines 36 and distance markers 38. The lateral edge lines 36 correspond to the lateral edges of the vehicle. The distance markers 38 each correspond to a selected distance behind the vehicle, preferably in uniform increments.

As shown in FIG. 5, the vehicle 11 (FIG. 1) has backed up sufficiently to superimpose the rectangle 24 on the potential parking spot 30. Once in this position, the driver can see that the vehicle 11 (FIG. 1) has sufficient room to fit in the parking spot 30. It is optionally possible for the length of the rectangle 24 to be the length required by the vehicle to fit in the parking spot instead of simply representing the length of the vehicle 11 (FIG. 1) itself. As will be understood by one skilled in the art, the length required by the vehicle (FIG. 1) to park in a spot is some amount longer than the length of the vehicle (FIG. 1) itself.

Once the driver has decided that the parking spot 30 (FIG. 5) is suitable, he or she may press another button on the dashboard to activate the parking assist system 10 (FIG. 1) in a parking guidance mode, as shown in FIG. 6.

In the parking guidance mode, the parking assist system 10 (FIG. 1) determines a target path for the vehicle 11 to follow in order to park in the spot delineated by the rectangle 24 (FIG. 6) at the time that the parking guidance mode was initiated.

When in the parking guidance mode, two representations are shown on the display 16. One is the aforementioned representation 34 of the vehicle's projected path at the current steering angle. The other is a representation shown at 40 a of a segment of the target path to reach the parking spot delineated by the rectangle 24 (FIG. 5).

Initially, the driver turns the vehicle's steering wheel until the projected path representation 34 of the vehicle substantially aligns with the target path segment representation 40 a. When they are suitably aligned, the parking assist system 10 may notify the driver that he/she can proceed to back the vehicle up along the target path. Alternatively, the alignment of the representations 34 and 40 a visually on the display 16 may itself be considered notification to the driver that the projected path suitably matches the target path.

Referring to FIGS. 7 a, 7 b, 7 c and 7 d, as the driver backs the vehicle up progressively along the target path segment, a distal portion 42 of the target path representation 40 a change from one colour to another, shortening the length of the proximal portion 44 of the representation 40 a that remains in the first colour. This gives the driver an indication of how much of the target path segment remains to be driven before another phase of the parking maneuver is to be made.

Once the vehicle has driven the entire target path segment, the parking assist system 10 selects the next segment of the target path for the vehicle to follow, and represents it on the display 16 as the representation 40 b shown in FIG. 8 a. The second target path segment representation 40 b guides the driver in the turn-in phase of the parking maneuver. At the point in time shown in FIG. 8 a, the vehicle's steering wheels are still pointed straight since the first target path segment which was just completed was a straight segment. Thus, at the point in time shown in FIG. 8 a, the driver's projected path represented at 34 is misaligned with the second target path segment represented at 40 b.

As the driver turns the steering wheel to align the vehicle's projected path with the target path segment, the projected path representation 34 becomes progressively aligned with and superimposed with the target path segment representation 40 b, as shown in FIG. 8 b. After the driver turns the steering wheel sufficiently, the vehicle's projected path is aligned with the vehicle's target path segment, as shown by the representations 34 and 40 b in FIG. 8 c. The target path segment illustrated in FIGS. 8 a, 8 b and 8 c may be the path at full wheel lock (ie. at the maximum steering angle the vehicle is capable of).

FIGS. 9 a and 9 b show the progress of the vehicle along the second target path segment. Once the vehicle has moved along the entire second target path segment, the parking assist system 10 selects the next (ie. third) target path segment for the vehicle to follow, which is represented in FIG. 10 a at 40 c. The third target path segment is the tuck-in phase of the parking maneuver and requires that the driver turn the steering wheel to the opposite limit. FIGS. 10 a-10 d illustrate the driver turning the wheel to bring the projected path into alignment with the third target path segment.

Once the projected path and third target path segment are aligned, the driver backs the vehicle up along the third target path segment. FIG. 11 illustrates the vehicle having completed almost all of the third target path segment. After the third target path segment is completed, the driver has completed the entire parking maneuver. Optionally he/she can drive forward if desired to adjust the spacing between the driver's vehicle and the vehicles in front and behind.

It will be noted that the parking maneuver includes three phases, a backup phase wherein the vehicle is backed up in a straight line (with the wheels pointing straight), a turn-in phase wherein the vehicle is backed up at full wheel lock in one direction, and a tuck-in phase wherein the vehicle is backed up at full wheel lock in the other direction. Providing target path segments wherein the wheels are pointed straight or are at full lock simplifies the process of aligning the projected path with the target path segment, and simplifies keeping the vehicle along the target path segment.

While backing the vehicle up along a target path segment, if the driver for some reason veers off the target path by more than a selected amount, the parking assist system 10 notifies the driver, and optionally aborts the parking maneuver.

Optionally, the parking assist system 10 can permit the driver to select whether the parking spot is to the left of the vehicle (as shown in the figures) or to the right of the vehicle. For a parking spot on the right of the vehicle, the turn-in and tuck-in phases would be mirror images of the turn-in and tuck-in phases illustrated in FIGS. 8 a-11.

It will be understood that the three target path segments need not all be the same length.

It will be noted that the rectangle 24 (FIG. 5) is at a fixed position behind and to the side of the vehicle. The target path for the parking maneuver is thus the same each time the vehicle is to be parked although it may be mirrored in the optional embodiment wherein the parking assist system 10 permits selecting a parking spot on the other side (ie. the right side) of the vehicle. As a result of the consistency in the parking maneuver, the parking maneuver need not be recalculated each time the vehicle uses the parking assist system 10. This permits the parking assist system 10 to operate using relatively inexpensive control hardware and software.

In the above description, the in-cabin display 16 was used as the human/machine interface and provided the driver with instructions visually/graphically for driving the vehicle into a parking spot. It is possible to provide instructions to the driver by other means in addition to or instead of using the in-cabin display 16. For example, the human/machine interface could include a speaker (eg. from the vehicle's sound system) and could emit audible messages to the driver via the speaker. Such messages could be instructions in any language, such as English. For example, an instruction could be given audibly to turn the vehicle steering wheel to a selected position (eg. full lock to the left). It will be noted that such an instruction would in effect inform the driver of the target path for the vehicle. In addition to the audible messages, or instead of them, a chime or a beep could be emitted at points in the parking process where the driver is supposed to carry out a new maneuver, to let the driver know that he/she is off course, to let the driver know that he/she is on course (ie. that the projected vehicle path matches the target path), or for any other suitable purpose.

In the above description a method and system were described for parallel parking into a parking spot. It is also possible for an embodiment of the invention to be provided for parking into a perpendicular parking spot 30 (see FIG. 12). A perpendicular parking spot 30 is a parking spot that is perpendicular to the direction of travel of the vehicle when driving by. Perpendicular parking spots are typically used in parking lots for malls, office buildings and the like. In the position shown in FIG. 12, the vehicle has already completed some portion of the parking process and is backing into the parking spot 30.

While the above description constitutes a plurality of embodiments of the present invention, it will be appreciated that the present invention is susceptible to further modification and change without departing from the fair meaning of the accompanying claims. 

The invention claimed is:
 1. A parking assist system for a vehicle, the parking assist system comprising: a camera mounted to the vehicle so as to capture image data representative of a rearward scene in a field of view of the camera; a display in the vehicle operable to display an image of the rearward scene derived from captured image data; a controller operable in multiple modes; wherein the controller, when operating in a first mode of the multiple modes, is operable to add an overlay to the displayed image of the rearward scene, wherein the overlay includes a representation of a target parking position; wherein the controller is operable in the first mode while the vehicle is being driven by a driver of the vehicle; wherein, when the transmission of the vehicle is in a reverse gear, the controller is operable in a second mode, and wherein, when operating in the second mode, the controller adds a second overlay and a third overlay to the displayed image of the rearward scene; wherein the second overlay includes a representation of a projected rearward path of the vehicle that is based on a current vehicle steering angle of the vehicle; and wherein the controller is operable to determine a target path for the vehicle to guide the driver to the target parking position and wherein the third overlay includes a representation of the determined target path; and wherein the parking assist system is operable to display the determined target path for the vehicle and the projected rearward path of the vehicle, to inform the driver of the projected path for the vehicle based on the current vehicle steering angle, and to inform the driver of whether the projected rearward path substantially matches the determined target path.
 2. A parking assist system as claimed in claim 1, wherein the representation has a length that represents generally the length of the vehicle.
 3. A parking assist system as claimed in claim 2, wherein the representation has a width that represents generally the width of the vehicle.
 4. A parking assist system as claimed in claim 1, wherein the overlay is a first overlay and wherein the controller is operable to operate the parking assist system in two operating modes which are selectable by a user, wherein in a first operating mode the controller is operable to add the first overlay to the image of the rearward scene, and wherein in a second operating mode the controller is operable to add a second overlay to the image of the rearward scene, wherein the second overlay includes a representation of a projected path for the vehicle based on a current vehicle steering angle, and a representation of a target path segment for the vehicle.
 5. A parking assist system as claimed in claim 1, wherein the target parking position is parallel to a direction of travel of the vehicle.
 6. A parking assist system as claimed in claim 1, wherein the target parking position is perpendicular to a direction of travel of the vehicle.
 7. A parking assist system for a vehicle, the parking assist system comprising: a camera mounted to the vehicle so as to capture image data representative of a rearward scene in a field of view of the camera; a human/machine interface including a display operable to display an image of the rearward scene derived from captured image data; and a controller operable in multiple modes; wherein the controller, when operating in a first mode of the multiple modes, is operable to add an overlay to the displayed image of the rearward scene, wherein the overlay includes a representation of a target parking position; wherein, when the transmission of the vehicle is in a reverse gear, the controller is operable in a second mode of the multiple modes, and wherein, when operating in the second mode, the controller is operable to determine a target path for the vehicle, to display for viewing by the driver an overlay of a projected path for the vehicle based on a current vehicle steering angle, and to display for viewing by the driver an overlay of the determined target path so as to inform the driver as to whether the projected path substantially matches the determined target path.
 8. A parking assist system as claimed in claim 7, wherein when the vehicle is moving along the target path the overlay includes a representation of the progress of the vehicle on the target path.
 9. A parking assist system as claimed in claim 7, wherein the representation of the projected path of the vehicle has a width that represents substantially the entire width of the vehicle.
 10. A parking assist system as claimed in claim 7, wherein the controller informs the driver of the target path segments via a speaker.
 11. A parking assist system as claimed in claim 10, wherein the controller informs the driver of the target path segments by instructing the driver to turn the steering wheel of the vehicle to a selected position.
 12. A parking assist system as claimed in claim 7, wherein the controller informs the driver of whether the projected path substantially matches the target path via a speaker.
 13. A parking assist system for assisting in the completion of a parking maneuver on a vehicle, the parking assist system comprising: a camera mounted to the vehicle so as to capture image data representative of a rearward scene in a field of view of the camera; a display in the vehicle operable to display an image of the rearward scene derived from captured image data; and a controller operable in multiple modes; wherein the controller, when operating in a first mode of the multiple modes, is operable to add an overlay to the displayed image of the rearward scene, wherein the overlay includes a representation of a target parking position; wherein, when the transmission of the vehicle is in a reverse gear, the controller is operable in a second mode of the multiple modes, and wherein, when operating in the second mode, the controller is operable to determine a plurality of target path segments for the vehicle to follow, and wherein, when operating in the second mode, the controller is operable to display overlays of the determined target path segments on the displayed image of the rearward scene and to display an overlay of a projected rearward path of travel based on a current steering angle of the vehicle.
 14. A parking assist system as claimed in claim 13, wherein the plurality of target path segments is three target path segments, including a first target path segment in which the vehicle is driven straight rearwardly, a second target path segment in which the vehicle is driven rearwardly with the steering wheels at full lock in one direction, and a third target path segment in which the vehicle is driven rearwardly with the steering wheels at full lock in the opposite direction.
 15. A parking assist system as claimed in claim 14, wherein the length of each target path segment remains constant from one parking maneuver to another.
 16. A parking assist system as claimed in claim 13, wherein the controller informs the driver of the target path segments via the display.
 17. A parking assist system as claimed in claim 13, wherein the controller informs the driver of the target path segments via a speaker.
 18. A parking assist system as claimed in claim 13, wherein, when the vehicle is reversing, the overlay includes a representation of the progress of the vehicle along the determined target path.
 19. A parking assist system as claimed in claim 13, wherein the representation of the projected rearward path of travel has a width that represents substantially the entire width of the vehicle. 